Why is my Mercedes radiator fan running on high speed?

Please try again later. This is a very common problem with the Mercedes radiator cooling fan running constantly on high speed. The problem in most cases is a bad ecm so in order to fix it the ecm will have to be replaced and programmed to work with your vehicle. Check the mass airflow sensor first.

What should the radiator fan be running at?

The fan continues to run at its maxiumum speed, regardless of the engine temperature. I allowed the car to run today from cold to just above 80 deg. C before sutting it off today.

What happens when air conditioner fan is running at high speed?

Why does my C300 4Matic run full speed?

I am a new owner of a 2010 C300 4Matic that I bought from an insurance auction – the car was a salvage car due to a front impact. I have repaired all of the damage, but there is one issue that I cannot figure out. Immediately upon starting the car, the radiator fan begins to run full speed, even though the car is stone cold. The AC is OFF.

The fan continues to run at its maxiumum speed, regardless of the engine temperature. I allowed the car to run today from cold to just above 80 deg. C before sutting it off today.

Why does my car’s radiator run so fast?

I’m not a Benz mechanic so what I’m stating is from an experience I had on my 2008 C300. Two things will make your radiator fan run on fast. Either a signal that the engine is hot or that the air conditioning condenser (located in front of the radiator) is telling it that it’s hot and to run fast to cool it down.

What are the symptoms of a bad cooling fan?

Common signs include the engine overheating, cooling fan only working at certain speeds, and the fan never turning off.

When do you turn on the cooling fan?

Once the coolant temperature sensor detects that the engine temperature has exceeded acceptable levels, the cooling fans will be activated to keep the engine cool. Many vehicles come equipped with cooling fans that operate on more than one speed setting.

What causes a Mercedes-Benz SL500 heater to not work?

Find the most common driver-reported problems that are to blame when a Mercedes-Benz SL500 has heater problems. Bad Switch/Blower Motor Resistor Assembly May C… Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower…

Why does my car’s cooling fan keep running?

It could be a sensor fault, but also the fan runs if there is an engine fault reported. Has the dealer run any diagnostics? It’s hard to see how it can be the fan if it runs…

What should I do if my fan is running at a constant high speed?

Confirm that there are no leaks at the sensor, that the air-conditioning is operating as expected and that the fan no longer runs at a constant high speed. Finally use the AssistPlus to run a Quick Test and ensure there are no new fault codes.

Why does the engine fan run all the time?

The sensor shown in the diagram is for air conditioning. The sensor we need to find is actually a temperature switch somewhere in the cooling system and may have failed safe in the closed position causing the fan to run all the time. what abut if i connect the car to the OBD II? i can bay one if that can tell me the problem within my car?

How does a radiator fan work when the AC is on?

The electric radiator cooling fan assembly is controlled by a thermoswitch located in the side of the radiator. At higher coolant temperatures, the switch closes to start the cooling fans. Any time the coolant temperature rises to higher than normal levels, the fan will start and continue to run until coolant temperature returns to a normal range.

Why are the cooling fans not working on my car?

1. Engine running hot 2. Cooling fans do not function 3. Cooling fans stay on at all times Average rating from 129,472 customers who received a Vehicle Engine Cooling Inspection. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool.

How to troubleshoot an electric cooling fan problem?

1.Has the Cooling Fan Actually Failed? 1 If the fan comes on when the AC is running at MAX, but doesn’t run when the engine is hot, check the temperature sensor… 2 If the fan fails to come on, first check for a fan blown fuse or triggered breaker. On older vehicle models, you may… More …

Why does my Jetta not have a cooling fan?

Simply the engine is not hot enough to turn on the cooling fan, its not hot enough outside, you are driving getting plenty of air flow through the grille to keep things cool without the assistance of the fan. Its possible that you have no problem at all. Was this answer helpful? I got a 2002 Jetta the cooling fans don’t turn on .

Why is my air conditioner fan running at high speed?

This problem is often caused by a faulty pressure sensor located on the air-conditioning condenser. If accessing fault codes, there are no relevant DTCs stored in the engine control module (ECM) or signal acquisition module (SAM). • Run a Quick Test to check for any relevant fault codes.

When does the car cooling fan turn off?

Again, the HVAC is off. Once the car is started, the cooling fan will remain on until the car is shut off. The fan is running as such a high speed you can hear it over the noise of the idling engine. Once I turn the car off the fan shuts off.

Is it normal for a car fan to run all the time?

This is normal in many vehicles, such as BMW or Mercedes-Benz. The radiator fan may run up to five minutes and sometimes longer. Unless there is an electrical issue, it may stay on all the time until it drains the battery. When the engine is running, the coolant circulates from the engine and flows to the radiator, where heat is dissipated.

What does it mean when Fan is running at constant high speed?

If it is higher, the air-conditioning control module presumes that the pressure is high and assigns the fan control module to run at 90% PWM actuation. Also check the AAC pressure at stand still / cold. This should be approximately 5 – 6 bar. Confirm that there are no wiring issues to the sensor. Pin 2 – Signal. Reference values:

Why is my 2002 LS radiator fan always running?

My 2002 LS radiator fan is always running and very loud. Does not matter if the engine is hot or cold. To me, it sounds like a fan speed control is stuck in high speed mode. The engine temp sensor appears to be working ok because the temp gauge is working properly and the engine is not over heating.

Why does the radiator fan only come on at 35 mph?

It rarely comes on at speeds over about 35 mph because at that speed enough air is forced through the radiator to keep the engine at about 198 degrees. I would start by looking for a blown 30 amp fuse under the hood.

Why is my engine cooling fan running at constant high speed?

There is no Schraeder valve on the sensor and removing the sensor allows the gas to escape into the atmosphere. Replace the sensor and confirm good location of the wiring connector. Locate wiring in order to avoid chafing of harnesses. Use the AssistPlus to check the reading in the climate control module.

Why are the cooling fans running in my 2004 Lincoln LS?

I noticed that my 2004 Lincoln LS V8 cooling fans are running allot when the car gets to normal operating tiemp. The gage doesn’t move once it gets to temperature. It starys right in the middle. The cooling fans have started to run for no reason.

Why does my car fan keep running after I Turn Off the engine?

Running cooling fans help cool down the engine even after you turn off the car. Common Causes. If your cooling fan runs for over 10 minutes after turning off the engine, you may have a problem that needs to be fixed. Here are some possibilities causing the fan to stay running longer. low coolant level, faulty coolant temperature sensor,

Why does my Mercedes Benz fan keep running?

Automotive information based around Mercedes-Benz information and repair assistance along with other makes and models. No matter what car you own or need help with, my tips and tricks and teachings can help you along the way. An error occurred while retrieving sharing information. Please try again later.

Why does my Mercedes Benz engine misfire so often?

Engine misfires are one of the most common problems we see in many Mercedes-Benz cars. To be honest, it is not because MB cars are weak in this area, but because most owners forget that spark plugs are wear items and need to be replaced at the recommended intervals.

Why does my ACC blower not turn on?

The ACC has a very common fault — the resister/ fan controller fails and the blower will run full blast and then not at all. The display stays on and works normally. The controller is mounted behind the glove box — I replaced mine in about 15min — you can get them online for around $100.00.. Change the cabin filter while you have it opened up.

When did the Mercedes Benz ML Class come out?

In this article, we consider the first-generation Mercedes-Benz M-Class / ML-Class (W163), produced from 1997 to 2005.

How long does the radiator fan stay on in a 2010 F150?

2010 ford f150 radiator fan stays on 2010 Ford F150, Radiator fan seems to be running on high more than it should. Fan kicks on about 30 seconds after vehicle is started and is extremely loud. Even kicks on when its a cooler day.

Where is the relay on a radiator fan?

The fan relay is often located in the engine bay’s fuse box, but the best way is to check your repair manual to find where it is located. Testing a 4 pin relay is often very straightforward. Remove the relay and give 12 volts to pin 30 and 85. Ground pin 86 and check if there is voltage coming out from pin 87.

Why are my cooling fans running at all times?

3. Cooling fans stay on at all times. If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times.

What should I do if my engine cooling fan is running at high speed?

Replace the sensor and confirm good location of the wiring connector. Locate wiring in order to avoid chafing of harnesses. Use the AssistPlus to check the reading in the climate control module. As the system is still currently empty, this should read 0 bar. Fill the system with the specified amount of refrigerant and oil.

How does the radiator feel when the car is running?

I allowed the car to run today from cold to just above 80 deg. C before sutting it off today. When one feels the upper radiator hose (driver side), it is HOT, and the air blowing near that side of the radiator appears to be hot. The lower radiator hose (passenger side) is COLD, and the air blowing near that side of the radiator appears cool.

Which is the hot side of the radiator?

When one feels the upper radiator hose (driver side), it is HOT, and the air blowing near that side of the radiator appears to be hot. The lower radiator hose (passenger side) is COLD, and the air blowing near that side of the radiator appears cool. The heat is also turned on full blast, and blows lukewarm/cool air.

What kind of heater does a Mercedes 124 have?

For all Mercedes 124 chassis cars from 1986 up to 1993 ONLY. This includes the 260E, 300E, 300D, 300CE, 300TE, and 400E Fits all Mercedes 126 chassis cars from 1981 to 1991. This includes the 300SD, 380SE, 380SEL, 500SE, 500SEL, 300SDL, 420SEL, 560SEL, 300SE, 300SEL, 380SEC, 500SEC, 560SEC.

What to do if your heater motor won’t work?

Options for repairing it yourself and saving big $$$. If your heater motor won’t come on, first check your fuse or relay. If you are not sure if the switches are the problem, we recommend you get the covers off and power the motor directly with a 12 volt power source.

Is the Mercedes Benz EQC 400 4Matic an electric car?

Really, its electric promise is simple. Driving it should be as easy, comfortable, and convenient as a gas- or diesel-powered Benz. A few days in rainy Norway this spring testing the EQC 400 4Matic revealed the first two gauntlets as cakewalks.

Why is the cooling fan running on high?

2007 Mercedes clk350 , why… 2007 Mercedes clk350 , why is cooling fan running on high ? As soon as car starts the cooling fan runs high, have checked ac temp sensor (is good) …still runs high regardless if ac is on/off.

What happens when your AC Fan is running 24 / 7?

Better dehumidification. When your fan is on “AUTO,” moisture is able to drip from the cold cooling coils and drain outside. When the fan is running 24/7, that moisture doesn’t have a chance to drip outside. Instead, it blows back into your house, and, as a result, your AC then has to work ever harder to suck that extra moisture out of the air.

How can I tell if my air conditioner is running at a constant high speed?

Fill the system with the specified amount of refrigerant and oil. Capacity information is found on the AAC refrigerant fill sticker, located under the engine hood (bonnet). Confirm that there are no leaks at the sensor, that the air-conditioning is operating as expected and that the fan no longer runs at a constant high speed.

Navigation